For large and extra-large instance types, no swap "device" is exposed, so I think having swap default to off is expected.
We could have a filesystem-level swap partition though, and use that for all instance types, but I don't know if that is a path we want to go down... that's a PM decision. We'd need this in the %post section of the ks file:
dd if=/dev/zero of=/swapfile bs=1024 count=$(($SWAP_SIZE_MEGABYTES*1024))
mkswap /swapfile
Then later in an initscript:
swapon /swapfile
echo Swap Status:
swapon -s
I do not think we should pursue this for the imminent 5.5 kernel 2 update, but possibly in a future release.